The organization of ribosomal genes in vertebrates.

Cortadas, Jordi; Pavon, M C

doi:10.1002/j.1460-2075.1982.tb01299.x

Cited by 28 publications

(13 citation statements)

References 12 publications

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“…The rRNA genes are represented in multiple copies throughout the genome of eukaryotic cells, varying in size and copy numbers from species to species (Long and Dawid, 1980;Cortadas and Pavon, 1982). These genes are clustered among many chromosomal loci, ordered in tandem in a "head to tail" manner.…”

Section: Resultsmentioning

confidence: 99%

Genomic organization of the rDNA cistron of the teleost fish Cyprinus carpio

Vera¹,

Molina²,

Pinto

et al. 2003

Biol. Res.

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The seasonal adaptation of the teleost Cyprinus carpio to the cyclical changes of its habitat demands physiological compensatory responses. The process involves profound nucleolar adjustments and remarkable changes in rRNA synthesis, which affects ribosomal biosynthesis. In this context, we have demonstrated that the synthesis of several proteins involved in ribosomal biogenesis as protein kinase CK2, ribosomal protein L41 and nucleolin, as well as U3 snoRNP, are differentially regulated in summer-acclimatized carp compared to the cold-season adapted fish. To understand the mechanisms involved in the seasonal regulation of rRNA gene transcription, we have been studying the carp rDNA cistron structure. Because the cis-elements that regulate the expression of the tandem organized ribosomal genes are located in the non-transcribed intergenic spacer (IGS), we analyzed the primary structure of the carp rDNA gene IGS. The gene organization is similar to that described from other vertebrate species, including numerous repetitive sequences, the transcription start site, and some potential cis-elements such as ribosomal enhancers, proximal terminator and transcriptional terminators. Ribosomal DNA is a remarkable case of gene duplication and has been used as a model to test the concerted evolution theory. We performed sequence comparison analyses of 18S rRNA coding sequences from carp with different species, data with which an unrooted phylogram was constructed.

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Section: Resultsmentioning

confidence: 99%

Genomic organization of the rDNA cistron of the teleost fish Cyprinus carpio

Vera¹,

Molina²,

Pinto

et al. 2003

Biol. Res.

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show abstract

“…In several autotrophic dinoflagellate species, cells in logarithmic phase were found to contain a twofold-larger amount of DNA than those in stationary phase (1). In most eukaryotes, rRNA genes are organized in tandemly repeated units (14), for example, 100 to 200 copies are present in yeast and 50 to 10,000 copies are present in mammals. Within the Alveolata, the number of rRNA copies ranges from 2 to Ͼ100.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the rRNA Locus of Pfiesteria piscicida and Development of Standard and Quantitative PCR-Based Detection Assays Targeted to the Nontranscribed Spacer

Saito

Drgon

Robledo

et al. 2002

Appl Environ Microbiol

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Pfiesteria piscicida is a heterotrophic dinoflagellate widely distributed along the middle Atlantic shore of the United States and associated with fish kills in the Neuse River (North Carolina) and the Chesapeake Bay (Maryland and Virginia). We constructed a genomic DNA library from clonally cultured P. piscicida and characterized the nontranscribed spacer (NTS), small subunit, internal transcribed spacer 1 (ITS1), 5.8S region, ITS2, and large subunit of the rRNA gene cluster. Based on the P. piscicida ribosomal DNA sequence, we developed a PCR-based detection assay that targets the NTS. The assay specificity was assessed by testing clonal P. piscicida and Pfiesteria shumwayae, 35 additional dinoflagellate species, and algal prey (Rhodomonas sp.). Only P. piscicida and nine presumptive P. piscicida isolates tested positive. All PCR-positive products yielded identical sequences for P. piscicida, suggesting that the PCR-based assay is species specific. The assay can detect a single P. piscicida zoospore in 1 ml of water, 10 resting cysts in 1 g of sediment, or 10 fg of P. piscicida DNA in 1 g of heterologous DNA. An internal standard for the PCR assay was constructed to identify potential false-negative results in testing of environmental sediment and water samples and as a competitor for the development of a quantitative competitive PCR assay format. The specificities of both qualitative and quantitative PCR assay formats were validated with >200 environmental samples, and the assays provide simple, rapid, and accurate methods for the assessment of P. piscicida in water and sediments.

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“…Fluorescence in situ hybridization (FISH) was performed basically according to Pinkel et al (1986), using a cocktail of 18S and 28S cloned fragments of the rDNA of Xenopus laevis (Cortadas and Pavon, 1982), and a 5S rDNA probe of the fish Leporinus elongatus, obtained by PCR (polymerase chain reaction) as described in Martins and Galetti (1999). The probes were labeled with biotin-16-dUTP by nick translation.…”

Section: Fluorescence In Situ Hybridizationmentioning

confidence: 99%

Chromosome mapping of 5S rRNA genes differentiates Brazilian populations of Leporellus vittatus (Anostomidae, Characiformes)

Aguilar

Galetti

2008

Genet. Mol. Biol.

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Among the anostomid fishes, the genus Leporellus is represented by only three species: L. nattereri, endemic of the Amazon River, L. retropinnis, endemic of the Piracicaba River, and L. vittatus, widely distributed in rivers from Peru, Colombia, Guianas, and different major hydrographic basins of Brazil. A cytogenetic study carried out on specimens of Leporellus vittatus from three major Brazilian hydrographic basins evidenced a karyotype of 54 metacentric and submetacentric chromosomes. C-banding analysis revealed the presence of large pericentromeric heterochromatic segments in all chromosomes and a telomeric block coincident with the NOR sites. Ag, CMA 3 or MM staining, and FISH with ribosomal probes located the 45S ribosomal genes on the terminal region of the long arm of the 12 th chromosome pair of all populations. Nevertheless, in the specimens from the Paraná and São Francisco Basins the 5S rDNA clusters were interstitially located by FISH on the long arm of the 2 nd chromosome pair, while in the specimens from the Tocantins-Araguaia Basin these sites were observed on the long arm of the 9 th chromosome pair and on the short arm of the 17 th chromosome pair. These data suggest that the species currently named Leporellus vittatus may comprise a complex of cryptic species.

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The organization of ribosomal genes in vertebrates.

Cited by 28 publications

References 12 publications

Genomic organization of the rDNA cistron of the teleost fish Cyprinus carpio

Genomic organization of the rDNA cistron of the teleost fish Cyprinus carpio

Characterization of the rRNA Locus of Pfiesteria piscicida and Development of Standard and Quantitative PCR-Based Detection Assays Targeted to the Nontranscribed Spacer

Chromosome mapping of 5S rRNA genes differentiates Brazilian populations of Leporellus vittatus (Anostomidae, Characiformes)

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